Portable screen



FIG. 1 is a fully assembled front view of our design;

FIG. 2 is a back view thereof;

FIG. 3 is a right side thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof;

FIG. 7 is a back isometric view thereof; and,

FIG. 8 is a front isometric view showing our design in an alternate partially assembled, exploded configuration.

The broken lines shown depict leg accessories that are environmental subject matter and form no part of the claimed design. 

CLAIM The ornamental design for a portable screen, as shown and described. 